Senate Democrats are still unclear on exactly how to proceed, procedurally, with gun legislation, with many key measures that would have been the heart of the bill failing Wednesday, sources said.

When the Senate returns Thursday morning, lawmakers will have to dispense with the two remaining amendments of the original vote agreement reached with Republicans on Tuesday. After that, it’s probable that Senate Majority Leader Harry Reid, D-Nev., will move onto an online sales tax bill, putting the gun package back on the calendar to be brought back up at an undetermined date. It’s also possible the legislation could stay in legislative purgatory for the remainder of this Congress if the vote dynamics of the bill remain unchanged.

A group of Democrats, however, favor staying on the gun package after the final amendments are dispensed with, a senior Democratic aide said. These members would like Reid to file a motion to cut off debate on the bare-bones underlying bill to put a period at the end of a process they feel Republicans have obstructed. That would likely result in a GOP-led filibuster of the bill, which could complicate the political viability of bringing it back for further debate.

Given that the important measures have already failed, however, there also seems to be an emerging consensus that further votes would just needlessly expose in-cycle Democrats from red states who already were put on the spot.

A disappointed Senate Majority Whip Richard J. Durbin, D-Ill., said he expects the Senate to come back to the gun violence issue at some point after members get heat over opposing the measure.

“I don’t think this is the end of it,” Durbin said. “It used to be that the [National Rifle Association] would win, we’d wait for another few years and think about it all over again.”

“That isn’t where we are today,” Durbin said. “We are now in the world of Gabby Giffords and Mayor Bloomberg and organizations that organize to come out and support those who are for gun safety and oppose those who aren’t.

Durbin said he was particularly disappointed by the failure of a bipartisan amendment to crack down on straw purchasers.

“That to me was incredible,” Durbin said. “I was a co-sponsor. I thought the NRA endorsed it. Leahy amended it to meet the NRA objections and they still all voted against it.”

President Barack Obama also vowed to continue the fight in an emotional Rose Garden speech after the Senate voted down the background check deal crafted by Sens. Joe Manchin III, D-W.Va., and Patrick J. Toomey, R-Pa.

Calling it a “pretty shameful day for Washington,” Obama asked Americans to put pressure on lawmakers to reverse course. He accused many those voting against the Manchin-Toomey amendment of being “intimidated” by a small number of gun owners who were operating on information from the NRA — an organization Obama said “willfully lied” in order to win the debate.